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More on Leopard, AOL, Reuters and the Universe
About yesterday's story about a recalculation of the Hubble constant that indicates the Universe is much older than the current conventional wisdom that it's about 14 billion years old, reader Toby Haynes (tjwhaynes) writes
I love it when I see reports like this. Stating that the age of the universe is 15.8 billion years old gives the impression that this is accurate to around 1 percent or better. The error bars on this sort of figure are probably closer to +/- 2 billion years or more, implying that the 99% percentile answer is something in the range 12-20 billion years. Most of the "measurements" over the last 20 years fit into that range. There is a tendency for the more recent publications to fall into the 14-16 billion year mark and that may simply be a reflection that that is the "accepted" answer.
I actually used to work on a team measuring the Hubble Constant using Radio Telescope data ten years ago — actually the same group who came up with 42 km s-1 Mpc-1 value which caused all the Douglas Adams H2G2 references (that was shortly before I joined). There was a lot of controversy over the value of the Constant back then and it is still a hot topic. Back then, the Hubble Constant was thought to have values anywhere from 30 km s-1 Mpc-1 up to 120 km s-1 Mpc-1 . The smaller the value of the Hubble Constant, the older the Universe is. Having a smaller value was desirable because it meant that the Universe was old enough to account for the oldest objects observed (about 16 billion years old). Think about that.
One of the points that struck me then was that the value of the Hubble Constant measured tended to be higher when measured using "more local" techniques and tended to be lower as techniques using more distant measurements were used. The Radio Telescope information gave us measurements based on object around or beyond a redshift of 1 (or, to put it another way, these clusters of galaxies observed were about half the age of the universe when the light left them).
Anyway, we'll be seeing more measurements of the Hubble Constant for many more years. Just remember the error bars!
Reader habig disagrees, writing
To that, Haynes repliesNo, the startling thing about recent cosmological work is that we do know this number to ~percent. The flagship for this new "precision cosmology" are the WMAP [nasa.gov] results [nasa.gov]. The number is weighing in at 13.7+/-0.2 billion years. Take a look at the tables of cosmological parameters in this paper and the carefully calculated error bars.
This particular press release's sweeping claims do overreach, as nicely summarized by Michael Richmond in a post above. M33 isn't at a cosmological distance, the observations being done by this project help to understand the lower rungs of the distance ladder, from which you can figure out distances to far-off galaxies and try to calculate numbers to independently compare to the microwave background fits. These results are one of many such distance calibrations, and have to be factored in statistically with the others. On the whole, several other means of figuring out cosmological parameters (such as the Age of the Universe) agree with the WMAP results within errors. You only get TFA's 15% increase if that is the only measurement you use to calibrate distances, throwing out all the rest.
Chewing through that paper (interesting one by the way) shows that those error bars are based on analysis of the data after processing. Therefore, those error bars on the age of the universe are assuming that the removal of foreground sources and fluctuations due to the Sunyaev Zel'dovich effect have been done absolutely correctly. No attempt (that I can see) has been made to model the errors arising from that procedure. That alone suggests that there are systematic effects which are not accounted for in those results.
I'm extremely skeptical of a lot of error bars on a lot of data. Confusion is a huge topic in radio astronomy (and I don't mean the chaotic, running-around, headless-chicken type of confusion) and I see paper after paper that really doesn't understand it, deal with it or present any full explanation of how errors in confusion analysis would propagate into the answers.
Of the several announcements from Apple's World Wide Developers Conference yesterday, the most controversial seemed to be the introduction of "Spaces," an implementation of virtual desktops for Mac OS X's next version, Leopard.
Reader bandrzej welcomed the introduction of virtual desktops, but pointed a finger at Apple for taking so long to introduce them:About time with the virtual windows! Took them long enough...all other major *nix based window managers have them. Makes their "photocopying" comment at WWDC seem double edged, eh?
mblase has a mitigation defense for Apple's tardiness, writing
In all fairness, Leopard's Spaces implementation looks like a quantum improvement on other virtual desktop managers I've used. (Granted, it's been awhile since I tried any since I was never very satisfied.) None of the other VDMs I recall were quite "Mac-like" enough — by that, I don't mean flashy and animated, but easy to use and understand.
They borrowed some design ideas from Expose, it looks like; you can view all four of your desktops at once; you can drag-and-drop windows from one to the other; and they all use the same Dock instead of using different Docks for each desktop, which is the one thing I always wanted.
Reader CatOne mostly agrees and adds some details:
I've played with Spaces briefly; it's nice.
You can configure as many virtual desktops if you want — the default is 4 (2x2) but you can add rows or columns as you see fit. I went to 16 (4x4) and that was fine... I don't know whether 36 or heck 81 would be manageable. I'm sure it would be RAM heavy ;-)
The ability to bind applications to individual "spaces" is nice, as is the ability to dynamically drag windows between them. Clicking on an application icon automatically moves you to the appropriate space; this should mean much less (where is that damn window, it's buried!) that I still experience, even on my 30" Cinema Display. I thought this would be enough space for that to not happen anymore; all I have now is *huge* browser and mail windows.
Is it a quantum leap in virtual desktop managers? No. But switching between them is quick, efficient, and easy (you can use control-space # to go to it, or control-arrow key)... so it really just gives you a desktop space many times your actual space... that's what it feels like. None of the cube effects a la You! desktops, which is slow and mostly eye-candy-esque.
On the disclosure by America Online that the company had inadvertently released more than a half million customer search records stripped of names but not otherwise sanitized (and thereby possibly exposing individuals to snooping), reader ivan256 wants to know
To that question, reader schwaang writesWhy were you ever under the delusion that aggregate data about your searches would be kept private? You don't even have an implied right to privacy when you send un-encrypted data across the internet. Not only are people stupid if they're upset about this, they're stupid if they're surprised.
Calling this is a consumer rights issue is a joke. There are no rights involved here other than ones that people made up after the fact because they were irrationally upset.
Maybe because AOL's privacy policy says so? First because it defines Member Information to include:
"information about the searches you perform through the AOL Service and how you use the results of those searches;"
And then it says:
"AOL will only share your AOL Member information with third parties to provide products and services you have requested, or when we have your consent"
"Keep reading," says ivan256:
Get down to the part about AOL Search, which has additional privacy terms. It is implied that they have your consent unless you opt out of the data collection.
While some commenters scoffed at privacy concerns in aggregated, semi-anonymized data, reader geekotourist says it's time to revisit "personally identifying information."
When AOL apologized today, the spokesperson said'"Although there was no personally-identifiable data linked to these accounts, we're absolutely not defending this."
Back in January, related to the story on how the DoJ demands and gets ISP data, AOL had said that "We did not comply with the request made in the subpoena," spokesman Andrew Weinstein said. "Instead, we gave the Department of Justice a list of aggregate anonymous search terms that did not include results or any personally identifiable information."
AOL- you need to rethink that phrase personally identifiable, because it doesn't seem to mean what you think it means. You're hiding behind one technical definition of PII, without concern about whether or not the results actually have PII. If you're releasing results with personally identifying information, then you cannot say you're not releasing PII. I'd written in January "I question this assumption by Yahoo, AOL, etc. that search terms, by themselves, have no privacy considerations because they've been separated from personal info. What if the search itself contains personal information? Are the search companies deleting the timestamps and randomizing the order of the search terms themselves? Because otherwise I could see personal info showing up." Obviously, half a year later, they still think that replacing a name with a number takes away the PII. They need to have a talk with, say, the Census Department, about why the department will withhold data about groups of businesses in a region. Grouped data can easily become PII data if you can tease out characteristics. AOL didn't even group the data!
As always, relevant quotes from the best.essay.evar on why privacy is a fundamental human right: "If information that is actually about someone else is wrongly applied to us, if wrong facts make it appear that we've done things we haven't, if perfectly innocent behavior is misinterpreted as suspicious because authorities don't know our reasons or our circumstances, we will be at risk of finding ourselves in trouble in a society where everyone is regarded as a suspect. By the time we clear our names and establish our innocence, we may have suffered irreparable financial or social harm..."
Yesterday's post about news agency Reuters' admission that it ran a digitally manipulated photo depicting the effects of Israeli bombing in Lebanon drew more than 500 comments. Joining many others in pointing out the obvious manipulation of the photograph, reader plover wants to know "Is Reuters complicit?"
The photo was so obviously manipulated as to be laughable. Anyone who's ever used the Clone Brush tool would immediately recognize it as having been manipulated, and anyone who's completely unfamiliar with digital photography would still question the regularity of the blobs of smoke.
Sure, this photographer is at fault, and you can make assumptions about his political motives for Photoshopping this image. But what's worse is how did Reuters let such a piece of crap into the system? The guys on SomethingAwful [somethingawful.com] or Worth 1000 [worth1000.com] all do a much better job, and that's just for the glory of the contest. They're not trying to pass their stuff off as "news." Even the guys at Fark [fark.com] aren't this bad (not even Heamer :-) No, this Photoshop was of "The Daily Show" quality — comically bad.
The only conclusion I can come up with is that Reuters isn't actually looking at the images that come in the door. Even if someone at Reuters had the same political agenda as the photographer, he should have had the good sense to deny that picture because the Photoshopping was so obvious. Actually, neither conclusion is good news for Reuters at all.
Piling on one last insult, Megane writes
It was done so badly that I could tell it was clone tooled by looking at the thumbnail of the picture.
Many thanks to the readers (especially those quoted above) whose comments informed each of these discussions.
Doesn't it? AaaaaaaaaaaaaaaaaRrrrrrrrrrrrrrrrGgggggggggggggggg gggg!!!!! Hey, that looks like a piece of cake.
(p.s. stupid caps checker... Bah!)
Cliff Claven
K.E.G. Party Chairman
Founding Leader of: Koncerned for Egalitarin Governance
"More on Leopard, AOL, Reuters and the Universe"
Oh, come off it, who really cares about the universe?
Where's the -1, Crackpot mod when you need it?
Now that AOL has released the search data, numerous sites to search through the data have appeared.
http://www.aolsearchdatabase.com/
http://aoldb.unwieldy.net/
http://aol.6brand.com/
http://www.aolstalker.com/
http://www.dontdelete.com/
Is this good, bad, or otherwise?
This is a fucking diaster for AOL. There will be lawsuits, and I'll bet you someone will die because of this (due to stalking, spouse finding out secrets, etc.). Use your imagination. This data is chock full of so much personal information, it's scary. I'm terrified that everything I've ever searched for in google is similarly logged in a data center somewhere and could be just as easily revealed but for whatever security they have in place, along with a dubious "don't be evil" guarantee.
If you're an AOL user you need to zcat this through grep ASAP for one of your unique searches, ASAP, to make sure you're not in the dataset. They can't ever "unrelease" this data.
This could take down AOL quicker than you can say "retention specialist". This is like Merck's VIOXX problem. THIS IS REALLY REALLY BAD. Got TWX? SELL SELL SELL. Holy fucking shit.
it's a blue bright blue Saturday hey hey
Here is a screenshot of Leopard that a friend gave me, yes, it dosent show much besides the icons, but here it is: http://paulmer2003.com/Leoparddesktop.jpg
Next you'll be telling us that chemists know more than biologists about the workings of organisms?
- These characters were randomly selected.
I tend to agree. Astronomers really have a tough time of it. Imagine being told to describe the beach while residing on a grain of sand. I personally take any conclusion about the universe with a pinch of salt simply because most of it is extrapolation. We have only been studying astronomy in only a in a brief moment when scaled to the age of the universe and only have been studying a spec when compared to the size of the universe. Then, we extrapolate conclusions-based on our limited understanding of physics- about the past and the future of the universe. Those conclusion are tenuous at best.
You don't have to be smart to use a Mac, you just have to be smart enough to buy one
Godless "plasma scientists" deny nature's 4-sided harmonious Time Cube!!!
See, I can link to crackpots too!
Two of them were really big at one point of time..enough to dwarf everything around them...then they imploded and became quite insignificant..now they are again showing signs of expanding back...
Come to think of it..even the Universe does the same..just over billions of years..
Notice what the desktop is missing.
Join Tor today!
Redshift is a problem of distance.
Think of the universe like a bubble.
We are at one point of the bubble, and a distant star system is at another.
Imagine setting off in a car from their star to ours.
At the point the journey starts, the distance is X.
All the time, the bubble is expanding, so the distance between us is growing bigger and bigger, so when you reach the original halfway point, you still have 3/4 of your journey left.
"nearby" objects aren't affected as much by the changes because the travelling time is small, but as the distance increases the redshift becomes more pronounced.
Thats my understanding of it anyway (affect/effect errors be damned).
liqbase
number 339461, he's on the second collection. That guy is freaken obsessed with tranny and transgender porn.
I currently use 'Virtue Desktop' on my Mac OS X system. It is ALMOST as good as Spaces, minus the Exposé-like effect of showing all of your desktops at once. The closest it has is an overlay that shows the relation of your desktops, and what programs are running in each (with a 'shadow box' showing the size of any open apps.) But you can't drag-and-drop rearrange apps between desktops, nor can you as easily switch desktops. As it is, you use Control-Shift-Arrow to switch desktops (they are in a grid that you can rearrange,) and Shift-Tab to show the 'desktop manager'. It both preserves your dock, and swaps desktops when you switch apps to go to the 'proper' desktop for that app. (Unfortunately, it means it automatically swaps desktops when an app steals focus.)
The fun thing is if you have a tit or light-sensor PowerMac or MacBook Pro, you can download a hack that lets you use either of those sensors to trigger desktop switching. So, for example, I have two desktops, one for my Mac OS apps, one for running Parallels in full screen. By simply waving my hand over the light sensor, I switch from Mac OS to Windows. (The app is called either 'SmackBook' or 'ShadowBook', depending if you want the tilt or light sensor version.)
Another non-functioning site was "uncertainty.microsoft.com."
The purpose of that site was not known.
After all the years of owning Macs, 10.5 is the first OS release that not only am I not excited about, but I pretty much don't care about at all.
Actually I am as excited abouit this release as anything. First of all, we don't even know about major new features they are not talking about yet.
But just out of what has been released, while there is nothing earth shattering what there si are a lot of really impressive upgrades across the board. Being able to just define a cropping of a webpage as a gadget? Boolean searches through the Spotlight API? ToDo functionality that might actually be useful? Document versioning finally rising to ascendancy? Being able to do slideshows or help someone with a computer remotley while I can see thier face to read body language? All very, very exciting... and that's on top of DTrace being included in OS X and XCode getting some great features!
As a user and a developer Leopard is a release with a lot of very cool things that ride atop the stable base that Tiger delivered. I honestly cannot see how someone could not be excited about this - unless of course they were an AC who in fact did not even own a Mac.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
But we have borrowed Expose in return.
Maybe once they have taken focus-follows-mouse (sorry, pet axe to grind - but it triples in value with translucent desktop objects) they can also copy the rest of the cutting edge eye candy in Compiz, like the insane yet cool cube thing and the rather more useful copacity.
Think of the Children; Sleep with your Sister
Sounds like someone didn't get to become an astronaut when they grew up. =(
Hey, are you the Sony Troll? You sure sound the same... Next, you'll be saying that OSX can't play games at 1080p...
How is your treatment going for your crack addiction? Did you go off your meds? Perhaps, this is a lame attempt at sarcasm? I know Spaces is a virtual windows knock but Linux window managers never did it quite as well as Apple has demonstrated. Time machine is another feature that can found implemented in other OS including windows. But, it is implemented in a way that it is accessibiltiy and easy to use. iChat makes colloboration actually possible without needing an IT person at your desk unlike Windows (even though Microsoft says otherwise). I think Apple is making great strides to broaden its appeal to more markets beyond creative types. If you don't value that, well you are not really running Apple anyway. In addition, I seriously doubt you are any good at marketing strategy .
You don't have to be smart to use a Mac, you just have to be smart enough to buy one
Remember that this was a very small preview geared towards devolpers, I'm sure once MacWorld roles around they will have some tricks up their sleeves. I am excited to see the stuff Novel is doing though, I really like XGL and compiz and hope to see more progress with those and Sun's Project Looking Glass. SUSE is currently holding me back from buying a Mac (well... SUSE and money) but Linux still is very far from "Just Working" to the degree Apple has attained. So far Vista has yet to interest me at all - the only reason I can see myself using it is for a work computer or if I stop making my PCs and pay the Microsoft tax.
Computers allow humans to make mistakes at the fastest speeds known, with the possible exception of tequila and handguns
The parent post is a quote from the Hitchhiker's Guide second series. The mod who rated it "Troll" should be ashamed.
I must agree with the first comment that the whole thing is anything but revolutionary as even the common Dock (a.k.a. taskbar) has been around for many years in KDE and I also believe in Gnome. Heck, even XP has had, in addition to third-party solutions, a native applet that does exactly that for quite some time (although obviously with a lot less eye-candy). Personally, I prefer Xgl's implementation (http://www.novell.com/linux/xglrelease/)which has a single desktop wrapped around 4 faces of a cube (this can be configured to use more than 4, of course). Not only do you not have to disengage from the desktop view to move windows around (you can use small viewport which is in the bottom right corner by default and in which all windows are visually represented), but the windows can coexist on two spaces at once (see screenshots on the link provided). This in and of itself feels a lot more organic to me than the constant switching back and forth between two views.
Firstly, a huge Leopard preview site is up at Apple's "sneak preview" site
But I don't know why everyone's so focused on Spaces. Yes, it's a great implementation of an old concept, but it's hardly the most significant feature announced in 10.5. That would have to go to the insanely innovative Time Machine.
Most Slashdot posters completely missed the point with Time Machine. Watch the video on Apple's site (or the WWDC keynote) to see... but a basic use case of what's cool:
1. Open Address Book and search for a person
2. Note that the person doesn't exist, but you knew you had them around at some point
3. Click the "Time Machine" icon...
4. Now Address Book appears in the Time Machine view, with the query still live
5. Click the "Back" arrow... and Time Machine zips back in time to a point at which the query returns something
6. Click on the record then the Restore button, and everything snaps back to the current, with the record now appearing in Address Book. No file system, calendars, or even leaving the current app involved, and the data was still directly selectable from within the current app's UI in the historical version.
This is something that hasn't been done by anyone, and isn't really comparable to Windows' new restore feature. Doing live queries through time? All while staying in your currently open app's UI? And having the historical data directly manipulable in the application's UI? This is really innovative stuff, and I don't think it got enough love in the Slashdot forums yesterday.
E pluribus unum
Dork, most astronomers who go to school learn in fine detail what a plasma is and how it works. Speaking as an astronomer, if you don't understand plasma physics then you don't have any right to call yourself an astronomer. Do you think Astronomy is just a bunch of lessons on how to use a telescope?
Well obviously then you do not know anything about Astronomy.
I dont even know where to begin with your post. Like someone earlier said, its like you are saying that chemists know more about how organisms work than a biologist does. It is an astronomers job to understand how a star (among many other things) works, and the study of plasma, nuclear fusion, and quantum physics all must be used to do this. It's not like Astronomers don't study other areas of science - they have to, because Astronomy is nothing more than a variety of branches of science (physics, chemistry, etc) applied to the study of the universe at large. The Astronomers that study the lives of stars are probably 'plasma scientists' as well, and those that are merely physicists (i jest) are more than likely in close communication with experts in that field.
Also, the postulated dark matter/energy has less to do with spiral galaxy formation than with the way that our universe is expanding. A lot of current data shows that our universe seems to be expanding faster than it should be based on how much mass we can observe. Therefore there must be some mass, or energy, that we cannot observe. This could take the form of halo's of brown dwarfs around galaxies, WIMP's (weakly interacting massive particles) or higher numbers of neutron stars than we currently know of.
Don't get caught up with the mysterious 'dark matter' label.
As for that link, well I just have this to say. Scientific conclusions are overwhelmingly adopted by the scientific community only when they have been tested to their limit and undergone criticism and analysis by a variety of experts. There is a reason Astronomers have come to the conclusions that they have, and it is not a grand conspiracy, and it is not to gang up on the team behind 'thunderbolts'.
Meta, Meta, Meta
I like your "describing the beach" analogy, but you perhaps give astrophysicists/cosmologists less credit than they deserve. We certainly do have to do a lot of extrapolation to say anything about distant stars, galaxies etc, but we do get some breaks. An obvious example is emission lines: you can take a sample of gas in the lab, pass a current through it, and look at the frequencies of light it gives off. That list of frequencies gives you a 'fingerprint' for the gas you're looking at, and it's well understood in terms of quantum mechanics.
Now, when we look at distant stars or galaxies, we see exactly those same series of lines (modified systematically by redshift as appropriate), which tells us that quantum mechanics works the same in those stars/galaxies as it does here on earth.
At the same time, there is still a huge potential for uncertainty when trying to get more specific information, which is what makes astronomy/astrophysics so hard (and interesting :-). The Hubble constant issue that brought this up is a nice example: The WMAP results constrain H very tightly, and therefore, if there's no dark energy or cosmological constant, the predicted age of the universe (it's just 1/H, although the weird astrophysics units of km/s/Mpc seem designed to make that non-obvious) can be found very precisely - that is, with a small 'statistical' uncertainty - it may not necessarily be very *accurate* - that is, the reported value is close to the true value.
That might seem done and dusted, but as others have pointed out, there are other ways of constraining the age of the universe. An obvious way of getting a lower bound is to look at the oldest things we can find. Globular clusters are believed to be very old, and by modelling the evolution of these galaxies suggests that they're older than the age given by 1/H.
It's further complicated by things like the results of the High z supernova search, which suggests the universe is accelerating in its expansion, and so 1/H isn't a good measure of the age of the universe.
So, given all that, which do we believe, and how do you summarize the "age of the universe" in one number? Answers on a postcard to any well-regarded, peer-reviewed astrophysical journal...
KDE Documentation Team: http://i18n.kde.org/doc
This theory buries the needle of my crackpot-o-meter. Grandiose claims: check. Delusions of persecution by mainstream science: check. Favorable comparison of the author to major science luminaries, suggesting they were on the right track, but not nearly as bright as the author: check. "Everything we know is wrong:" check. Creation of a whole new field of science out of whole cloth (plasma scientists?): check.
The theory is that stars don't make energy through nuclear fusion, but some wacky kind of electrical process. 'Nuff said.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Linux WMs? *shrug* Linux is still young in the GUI design realm.
This sounds like it has a lot of features from SGI's 4Dwm. My default 4Dwm has a handful of desktops and a global desktop. I can have a window reside on multiple desktops at different coordinates, on just a single desktop, or on every desktop at the same coordinates with the global desktop. I can view all of the desktops in a thumbnail metawindow and drag any window from one desktop to another. I have another metawindow with a icon for every open window across all desktops, and clicking on an application will switch to the appropriate virtual desktop. I have keyboard shortcuts for nearly everything (including switching desktops, switching windows, switching focus among vertically stacked windows, etc), as well.
I'm not trying to troll. I'm just saying, look around a bit before saying that Apple is doing something new/better. SGI has done a lot of really neat things in the GUI realm that I haven't seen anywhere else (yet?).
This is the longest slashdot article I've ever seen.
All I can say is.... wow.
Remember, this is the Worldwide DEVELOPER Conference. This isn't showing everything about Leopard -- it's just showing the things that Developers might want to build upon.
If I was a Mac developer, I'd be pretty excited about:
1) The new iCal API, and the open-sourcing of the iCal Server (if a team to work quickly, they could have compatible clients for Linux and Windows by the release of Leopard -- take that Exchange!)
2) Core Animation - I find myself using different apps, and thinking how usability could be increased, and the program actually simplified if there was a small amount of 3d animation
3) RoR on the server
4) Complex syntax in Spotlight would be useful in a thousand smaller projects
If I were a business user, I'd be excited about:
1) A replacement for outlook/Exchange
2) iChat's Virtual Keynote
And, I personally, am excited about
1) Time Machine!
2) Turn any website into a widget
3) Dashcode
4) Spaces -- yes, I of course have Virtual Desktop, but a free and simple and beatiful replacement is a good thing.
5) iChat's Screen Sharing -- I've been trying to convert a friend to Mac, but she's worried that I don't live in the same city to do tech support. As of this spring -- problem solved!
6) QuickLook in Spotlight
Only 10 Leopard features were demoed for a developer conference, and the rest was kept "Top Secret." Just wait until MWSF07. We haven't even seen the resolution-independent GUI yet (introduced in Tiger's window manager but not fully implemented).
"Sufferin' succotash."
Organic chemists, yes.
But at the very least, biologists and organic chemists share and incorporate information readily. They have to; the connection between the disciplines is obvious.
The connection between astronomy and plasma physics wasn't until we figured out what stars were made from.
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Luckily Apple use better principles to direct their development than simply considering what gets you excited.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
Actually, red/blue shift is only about relative speed, and is a function of the doppler effect.
If you accelerate towards an object at relativistic speeds (anything above, say 10% c), it becomes bluer. This is because the light waves are coming to you at a faster rate than they would if you were a static distance from the object. Similarly, as you accelerate away, it becomes redder.
How does this apply to stars, and how does it help us find out the speed at which they're traveling relative to us?
Say the spectra lines from a star are like this:
| | | | |
Well, none of the spectra patterns you know of match up, but if you move it to the right by an amount (shift it to the blue), it matches up exactly with the spectra pattern for a hydrogen burning yellow star:
| | | | |
Because of this, we know that the star is hydrogen burning and is moving away from us. The amount of the shift tells us just how fast; you can calculate it in much the same way doppler radar calculates how clouds move in a weather pattern.
It's called 'Red Shift' because its spectra pattern has been shifted towards the red.
A simpler experiment. Go commit a crime. Wait for a police car to fly by, sirens blaring. The pitch of the siren changes as it approaches and moves past, yes? As you're handcuffed, you may think to yourself how, because of the spectral analysis you do in your head, as well as the simple pattern recognition, you knew immediately that not only was it the fuzz, and that you should get the hell outta there.
But, like the good student you are, you stayed and completed your lesson. Hooray for science! I'll see you in 10-15.
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The easiest way to tell if a person is a fanboy is to look at their sig. You replied to an Apple fanboy, but it could have just as easliy been a Linux or Windows fanboy.
Yes, but the distance between the stars is growing all the time, consider what would happen to the pitch of sound along a tunnel with a 5mph wind going in one direction and you and a police car at either end.
What would happen if the wind speed dropped or increased?
liqbase
Would this be considered a Slashbackslash or Backslashback?
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
Mod parent +i, "Weird".
come on guys, what with wireless laptops, just pull up outside some 'innocent's' house and use thier unprotected wireless modem and search/download away - my mate's ntl(UK) wireless modem came completely unprotected (default setup) and was easily used from outside, so is any of this actually legally traceable and is it down to the modem owner for whatever searches/downloads are performed - these default setups must be manna from heaven for people who want to disguise their habits/practices.
It's further complicated by things like the results of the High z supernova search, which suggests the universe is accelerating in its expansion, and so 1/H isn't a good measure of the age of the universe.
We usually talk H(t) (H as a function of time) for that exact reason.
The grand parent's post is really funny, especially after listening to a bunch of atomic/plasma physicists talking about theoretical cross section of some high atomic number species. They would casually say, "the value could be off by a factor of two or three, but it's better than nothing, right?"
It is indeed better than not knowing at all. But they do things the way astronomers do sometimes just as well. Only accurate to an order of magnitude. 1 or Pi, what's the difference?
Having said that, I don't agree with the grand parent's post. But I do say this: astronomers tend to be much more sloppy in their error calculations. I am pretty sure that there are some missing systematic errors creeping into this new Hubble Constant values. For christ's sake, they only use one data sample there!!
I think Rueters needs to lay off the crack... heck just label the images fake and call it satire. http://www.freakingnews.com/default.asp
As a star accelerates away, the red shift becomes more pronounced. This is gravity neutral, so the wind is irrelevant in this case (gravity doesn't slow light; it just bends it; light at a black hole, for example, is traveling at its normal ~300Mm/s, but in very tight circles around the singularity (theoretically)).
See, the doppler effect is dependant on speed. Since acceleration is change in speed, it causes the shift to increase. We can tell the universe is accelerating outward because of the speed at which spectra shift.
Now, on to the police car version: If the 5mph is away from you, you may be unlikely to hear the police car; the compression waves emitted by its siren may (depending on how loud it is and how long the tunnel is) be overcome by the movement of the air it's compressing. At the very least, the siren would be quieter.
If it's travelling towards you, the siren would be louder.
I'm unsure of how the wind would affect the pitch of the siren, but I can guess it would cause the waves to behave much in the same way as doppler, since the transverse waves would be coming at you at faster or slower rates.
On to "Dark Matter". It doesn't exist as is found in popular sci-fi. Dark matter is an all-encompassing term for stuff we can't see, whether by radio emissions or by telescope. There's a lot we can't see. Truth be told, our idea of the mass of the universe is based on using what we CAN see as a statistical sample, and an estimate as to the extent of the universe, using its known age and acceleration rate as a guide. 'Dark matter' just makes up the difference between that estimate and the mass the universe should have, mathematically speaking, to give us our observed data.
We can't see it, yet we know it's there. So it's dark. Get it?
That's not to say it's some extraordinary form of matter (though theoretical physicists, astronomers, and sci-fi writers love to play with odd matter ideas). It could be something as lame as an inordinate number of accretion discs and non-emitting bodies. It could be black holes or MECOs. We just don't have the data.
To paraphrase the Hitchhiker's Guide, the universe is big. I mean really, mind-bogglingly big. As such, cataloguing all its macroscopic contents (i.e. stars, planets, etc) is going to take a while longer than a run down to the chemist's.
110100 1101000 1101000 1100110 0 1101111 1101000 1100011 1
Why do people keep saying this? Compiz does everything Apple demonstrated, just as well. Moving windows between workspaces? Just drag them to the edge, the cube will rotate. Show *all* workspaces? Control-Alt-Down will "unwrap" the cube.
OSX still has a ways to go to catch up to Compiz.
This /. digest is someone out of left field... I read most of the comments gratuitously repeated above *in the story they are connected with*. Maybe it's just me, but what's the benefit of this new digest (or did I just miss something)?
If it becomes commonplace, please provide a category for it so we can opt-out.
The universe is not something you just dump something on. It's not a big truck.
It's a series of bubbles.
And if you don't understand those bubbles can be red-shifted and if they are red-shifted, when you look at it, it gets in line and it's going to be delayed by anyone that puts into that bubble enormous amounts of speed, enormous amounts of speed...
I just the other day got, a universe appeared red-shifted, so what I saw yesterday was actually the universe at 10 o'clock in the morning on Friday. Why?
So... 64-bits. All the other x86 operating systems out there seemed to have a large hiccup during the x86-64 transition. Apple claims Leopard will run 32 and 64 bits side-by-side, top-to-bottom in one OS that supports everything. Maybe I missed something. Why was this so hard to do with XP and Linux? Did Apple do something exceptionally clever? Is it their lack of required legacy support? How did they pull this off? Or was this not as surprising or significant an announcement as it seemed to me?
E pluribus unum
It's not hard.. XP and Linux both run 32 and 64 bit apps side by side. The problem (and Apple will experience the same) is that plugins, drivers, etc, must be the same as their host application.
A 64 bit version of Safari will *not* have Flash support, since the plugin is a 32 bit plugin.
While I agree with you in principle, I really don't think it's Subversion in particular. Unless you have information that you feel substantiates that, I think that this is more like the old VMS file system than any type of SV/CVS/code-version-control scheme. It seems to be implemented on a much lower level, and with a greater degree of system integration than an SV-based system would provide.
Plus, using SV just doesn't seem consistent with other stuff they've done in the past; this seems like an in-house project. Apple has a tendency to only use existing codebases occasionally, and when they do, they make a big point of it. Since nothing has been mentioned, I think it's way more likely this is something proprietary they've cooked up (unless HP licensed them the old OpenVMS stuff).
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
It's a holdover from NextStep/OpenStep.
If I Were a Designer Id Like
Personal Tags on the Files
That certainly sucked.
I'm glad to see you're all a very open minded sort.
IMarv
I honestly cannot see how someone could not be excited about this - unless of course they were an AC who in fact did not even own a Mac.
I own a Mac, and I am not interested, and I can't see how you ARE interested. I'm still running Panther because it does what I want it to do without extra bloat. My buddy has Tiger or whatever they named the newest OS, and I don't see any difference besides the Konfabulator thing which is almost completely useless and a waste of cycles. And I run Windows XP at work, and frankly, prefer that over OS X in many cases. I'd run Linux except my Apple wireless card (of course) is the least Linux friendly hardware known to man.
MOST people spend 90% of their leisure computer time doing email or surfing the web. The rest of this stuff is just unnecessary gimmicky crap that keeps keeners upgrading every year.
"...a lot of really impressive upgrades across the board. Being able to just define a cropping of a webpage as a gadget? Boolean searches through the Spotlight API? ToDo functionality that might actually be useful? Document versioning finally rising to ascendancy? Being able to do slideshows or help someone with a computer remotley while I can see thier face to read body language? All very, very exciting... and that's on top of DTrace being included in OS X and XCode getting some great features!..."
Do you hear yourself? Who uses this stuff? Are you the last true Slashdot nerd? Jeezus. There's a lot of Apple astroturfing going on here, but you're not one of them. Your stuff is way too weak.
Then why are there two separate versions of XP, one for 64-bit and one for 32-bit? Why couldn't Microsoft do what Leopard has apparently done in that respect?
E pluribus unum
Only 10 Leopard features were demoed for a developer conference, and the rest was kept "Top Secret."
They pulled in DTrace from Solaris and added a cool UI to it. I'm keeping my fingers crossed that they are also pulling in containers and doing the same thing. I'd kill for that functionality, especially combined with VM, but I'm sadly not expecting it. If they were moving to containers, they probably would have wanted to give developers more of a head start on making sure their apps run smoothly with them, and would have announced them. Still, I can hope.
Because not all PCs are 64 bit. Apple can put out a 64bit-only version of OSX because they manufacture the machines it comes with.
Apple does the whole fat binary thing - a single piece of software with both 32- and 64-bit code inside. A 32-bit machine will only see the 32-bit code. A 64-bit machine will see the 64-bit code.
... interestingly, Apple's fat binaries can be used as containers for any number of code variations. We could see a single fat binary that encloses 32-bit PPC code, 64-bit PPC code, 32-bit x86 code and 64-bit x86 code. There's no limit on this, and you end up with a single installable package for all versions.
It's not light on space, but since you're only doubling up on executable code (which is a small part of many applications) and drive space is cheap, it's a good solution.
Microsoft doesn't do this, although I'm not sure why not. Maybe they just want a 'cleaner' system, all 32-bit or all 64-bit and never the twain shall meet.
No, that's untrue. It's possible because they combine 32-bit and 64-bit versions into the executables. Identical copies of Leopard will be able to run on 32-bit and 64-bit processors.